3D printed electrospun nanofiber-based pyramid-shaped solar vapor generator with hierarchical porous structure for efficient desalination

•Pyramid-shaped evaporator based on nanofiber was developed by 3D printing.•High light absorptance and low enthalpy of evaporator improve the evaporation rate.•Convective flow promotes more vapor generation relying on hierarchical structure.•Self-cleaning property enables the evaporator to be used for long-term desalination.